Inkjet printing typically involves the use of water based inks. These water based inks interact with papers differently than inks used in other printing systems such as web offset printing. In particular, water based inks can cause print defects, such as bleed and mottle, and can cause paper deformities, such as cockle, curl, and show through of the text onto the opposite side of the page. These defects result in a need to limit the total amount of ink applied to the paper per unit area of a printed image. This limitation is often referred to as the upper ink limit (UIL) used for data processing for the printing system. The UIL necessary for one paper may not be the same as that appropriate for another paper, due to differences in paper type, weight, and coating. Thus, for each paper used on a given inkjet printing system, a different UIL needs to be specified by the user.
In the field of production printing, the ability to print text of various hues and saturations is commonly desirable. In order to achieve this range of colors, text may be printed using one or more colors of ink. Most commonly, process color prints are made using four inks: cyan, magenta, yellow, and black. Due to the defects mentioned above and the fine level of detail needed to render smaller point sizes of text and certain fonts with small features such as serifs, all possible ink loadings are not always acceptable. In particular, higher ink loads often result in printing defects, such as “ink bleed” that may cause small point sizes of text to be of unacceptably low quality or entirely illegible. The UIL allowable for text is partly dependent on the particular font and point size of the text, as well as the particular paper stock used for printing.
Typically, print defects are avoided by limiting the amount of ink that is used when printing smaller point sizes of text. The use a single ink limit for all colors of text is not often the most effective approach because when more than one color of ink is used for a particular text color a higher level of total ink might be permitted than for a text color that is created using only a single color of ink. The press operator or graphic designer may, therefore, specify several different total ink limits for small sizes of text based on whether the text is composed of one or more colors of ink. Empirically determining each of these limits for each paper and system configuration can be a tedious process.
A need exists for a series of steps to derive automatically the total ink limits of multi-ink texts using user supplied limits for text colors composed of just one or two inks. A need exists for a series of steps that enable the automatic adjustment of data coming into an ink jet printer and the use of these derived limits saving a user time and money for manually inputting two ink limits. A need has existed for a user to simply input one or two values for single and two-ink limits derive the remaining ink limits and apply all these ink limits to all parts of a print job regardless of size. The present methods meet these needs and save a user a significant amount of time and labor